1. Field of the Invention
The present invention relates to a multi-mode terminal, and more particularly to a method and apparatus for performing a Non Access Stratum (NAS) procedure in a multi-mode terminal.
2. Discussion of the Related Art
Wireless mobile communication technology is being rapidly developed not only for voice communication but also for high-speed transmission/reception of data. Nowadays, a fourth generation mobile communication technology, for example, a Long Term Evolution (LTE) wireless communication system is a focus of attention. However, when a fourth generation communication network and a third generation communication network coexist, a mobile communication terminal or a mobile communication data card must include not only fourth generation mobile communication technology but also third generation mobile communication technology, which is still highly prevalent globally. Therefore, in order to simultaneously support next generation mobile communication technology and legacy mobile communication technology, a mobile communication terminal having a dual modem processor and a data-card type device (hereinafter referred to as a multi-mode terminal) are needed.
The multi-mode terminal includes two modems having different communication schemes so as to support different communication schemes using the two modems. Generally, the dual modem devices have been widely used in a region including heterogeneous communication networks. As representative examples of the dual modem device, a Long Term Evolution (LTE) wireless communication device and a Code Divisional Multiple Access (CDMA) communication device are being intensively researched by many developers and companies.